Naive kotlin-jdk-headers.jar usage implementation

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java

@@ -132,10 +132,22 @@ public class JavaDescriptorResolver {
             public boolean contains(VirtualFile file) {
                 return myBaseScope.contains(file) && file.getFileType() != JetFileType.INSTANCE;
             }
+
+            @Override
+            public int compare(VirtualFile file1, VirtualFile file2) {
+                if (isInJdkHeaders(file1)) return 1;
+                if (isInJdkHeaders(file2)) return -1;
+                return super.compare(file1, file2);
+            }
         };
         this.semanticServices = semanticServices;
     }
 
+    public static boolean isInJdkHeaders(VirtualFile file) {
+        // TODO: need faster check
+        return file.getUrl().contains("kotlin-jdk-headers.jar");
+    }
+
     @Nullable
     public ClassDescriptor resolveClass(@NotNull PsiClass psiClass) {
         String qualifiedName = psiClass.getQualifiedName();

idea/src/META-INF/plugin.xml

@@ -79,6 +79,8 @@
       <java.elementFinder implementation="org.jetbrains.jet.asJava.JavaElementFinder"/>
       <java.shortNamesCache implementation="org.jetbrains.jet.plugin.caches.JetShortNamesCache"/>
 
+      <java.elementFinder implementation="org.jetbrains.jet.plugin.caches.JdkHeadersFinder"/>
+
       <editorNotificationProvider implementation="org.jetbrains.jet.plugin.quickfix.ConfigureKotlinLibraryNotificationProvider"/>
 
       <psi.treeChangePreprocessor implementation="org.jetbrains.jet.asJava.JetCodeBlockModificationListener"/>

idea/src/org/jetbrains/jet/plugin/caches/JdkHeadersFinder.java

@@ -0,0 +1,33 @@
+/*
+ * @author max
+ */
+package org.jetbrains.jet.plugin.caches;
+
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vfs.JarFileSystem;
+import com.intellij.openapi.vfs.LocalFileSystem;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.NonClasspathClassFinder;
+import org.jetbrains.jet.plugin.compiler.CompilerUtil;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.List;
+
+public class JdkHeadersFinder extends NonClasspathClassFinder {
+    public JdkHeadersFinder(Project project) {
+        super(project);
+    }
+
+    @Override
+    protected List<VirtualFile> calcClassRoots() {
+        File jdk_headers = CompilerUtil.getJdkHeadersPath();
+        if (jdk_headers == null) return Collections.emptyList();
+
+        VirtualFile jarVfs = LocalFileSystem.getInstance().refreshAndFindFileByIoFile(jdk_headers);
+        if (jarVfs == null) return Collections.emptyList();
+        jarVfs.refresh(true, false);
+
+        return Collections.singletonList(JarFileSystem.getInstance().getJarRootForLocalFile(jarVfs));
+    }
+}

idea/src/org/jetbrains/jet/plugin/compiler/CompilerUtil.java

@@ -29,4 +29,13 @@ public class CompilerUtil {
 
         return answer.exists() ? answer : null;
     }
+
+    public static File getJdkHeadersPath() {
+        File compilerPath = getDefaultCompilerPath();
+        if (compilerPath == null) return null;
+
+        File answer = new File(compilerPath, "lib/kotlin-jdk-headers.jar");
+
+        return answer.exists() ? answer : null;
+    }
 }